Any way to know amplifier idle power consumption? (wattage at wall)

[Digby]

Save using a power meter at the socket, is there any way to know an amplifiers background wattage usage, not in a standby mode, which it has to be awakened from, but an idle, immediately ready to play music state. Do manufacturers provide this information?

If you had to guess, which amplifiers would be the most efficient when on, but idle (not in a standby state) - would this be class D amplifiers or is their efficiency more so when driving a load?

 

[DVDdoug]

There is a gizmo called Kill-A-Watt. If you want to measure power, you need a power meter, or you can measure current ans calculate power, although this is not as accurate with inductive loads.

I wouldn't expect much difference at idle. It depends on the design so it would depend on the particular amplifiers. A class-D amplifier is more likely to have a switching power supply so the power supply itself probably uses less power than a "linear" power supply (before considering the amplification circuitry).

 

[Digby]

I wouldn't expect much difference at idle. It depends on the design so it would depend on the particular amplifiers.

There is a stark difference between an old pioneer amp I have from the 1980s (10w idle) and two powered speakers (40w idle). What with electricity prices going mad over here, this makes a big difference over the year, almost £150.

 

[fpitas]

At a guess, powered speakers have a CPU and DSP that draw power all the time.

 

[NiagaraPete]

From the Genelec G Five manual

Mains voltage​

100, 120, 220 or 230VAC 50/60Hz according to region

Power consumption​

ISS Active
≤0.5 W

Idle
≤10 W

Full output
170 W

 

[NiagaraPete]

Genelec uses ISS same thing.

 

[Digby]

At a guess, powered speakers have a CPU and DSP that draw power all the time.

Which should be superfluous if they are connected to a PC which can do its own DSP?

From the Genelec G Five manual

The speakers I'm using are Behringer, the standby function is trash, as with so many speakers. I used some expensive Hedd speakers that needed extreme volumes to come out of standby. I would rather not have the jump scare.

I also don't like the lag of playing music and then sitting and waiting for the speakers to respond either and missing the first 5-10 seconds of music/audio. I listen to stuff too intermittently, it is highly annoying.

 

[FrankF]

This wifi Kasa switch will turn the amp on and monitor power usage via a phone app. Been using for a couple months without issue.

kasa switch

 

[fpitas]

Which should be superfluous if they are connected to a PC which can do its own DSP?

Of course.

 

[Digby]

This wifi Kasa switch will turn the amp on and monitor power usage via a phone app.

This needs me to have the amp in my possession. I have a device like this to measure equipment I already own, but I'd like to know the idle (not standby) power of stuff I do not own, before purchasing.

 

[dasdoing]

It probably corelates with the power?
my PA speakers are rated 500W and manual says: 230mA@100Vac / 180mA@127Vac / 120mA@220Vac

 

[Blumlein 88]

If the people making or selling the device don't list it in specs then you can only guess. Anything class D is not pulling much power at idle. Best chance is downloading the manual for what you are considering to see if it is listed. It often is. Otherwise someone will have to measure it.

 

[Digby]

BTW for those interested (how exciting! I hear you cry), UK electricity is going to be 52p per kWh with at least 50p daily standing charge in October. Appliances I never gave a second thought to are quickly becoming real money burners.

 

[Chr1]

Just plugged a power meter into my Pioneer SC-LX86 AVR and it's using 79W at idle. Class D...

 

[mansr]

At a guess, powered speakers have a CPU and DSP that draw power all the time.

A few watts at most.

 

[restorer-john]

Just buy a good quality plug in-in-line power meter. Not one with wifi, bluetooth and sophisticated calculations of tariffs and cost- that's no good for what you want in this instance. You want something you can carry with you and check a product before buying?

I've got several and they are all accurate, only cost about $30 each.

They provide:
Current (continuous)
Current (peak)
Voltage (actual live voltage)
Wattage
Wattage (peak)
Power factor of connected item (cos θ)

I wish they were backlit as they are a little hard to see, but otherwise awesome.

Get one that is accurate at low consumption and high. Test them with say a 40w incandescent and a kettle/heater at 2400W. The PF should show 1 (for purely resistive) and that tests the accuracy of the current shunt at low/high drops. Good ones are trimmed in the factory. Then test the PF with an LED light of 10W or less. It should give you the actual PF and rated wattage. I have about 5 of them from various brands and they all read within <1% of each other on the same loads.

The last Aldi unit I bought sits on my bench permanently plugged in. It's several years old.

 

[restorer-john]

here's one that looks like it covers all the bases I listed above. Appears to have a PF reading as well.

12.78US $ 50% OFF|Digital Energy Meter Kwh Ac Power Meter Wattmeter Wattage Electricity Eu French Us Uk Au Measuring Outlet Power Analyzer - Energy Meters - AliExpress

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www.aliexpress.com

This is funny:

 

[julian_hughes]

There is a gizmo called Kill-A-Watt. If you want to measure power, you need a power meter, or you can measure current ans calculate power, although this is not as accurate with inductive loads.

I wouldn't expect much difference at idle. It depends on the design so it would depend on the particular amplifiers. A class-D amplifier is more likely to have a switching power supply so the power supply itself probably uses less power than a "linear" power supply (before considering the amplification circuitry).

I have one of those, or at least something that does the same job. It spends months, or even years, unused and then suddenly becomes indispensable! I built a new home server recently (to replace an ancient HP Proliant Mini Server) and was hugely relieved to discover that despite being powered by a 650W PSU it actually spends 99% of its life drawing about 40W. This is the kind of info that lets grumpy middle aged men sleep at night.

 

[antcollinet]

BTW for those interested (how exciting! I hear you cry), UK electricity is going to be 52p per kWh with at least 50p daily standing charge in October. Appliances I never gave a second thought to are quickly becoming real money burners.

Is that before or after Ms Truss decided to buy all our leccy for us using our children's money?

 

[RandomEar]

I don't know if they are the most efficient, but some pretty efficient amps are

• Aiyima A07, around 7 W in idle (measured)
• SMSL AO200, around 10 W in idle (measured)
• Amps with Purifi 1ET400A modules, around 13 W in idle (1,7 W per channel + 9 W for SMPS)

I'd guess that other amps using TPA3255 or MA12070 chips will be in a similar range, but you'd have to check each one to be sure. The upcoming Hypex Nilai500 module will probably be close to this, too.